Ammunition

ABSTRACT

Caseless and semi-caseless rounds of ammunition produced at very high production rates in which a molded cylinder of propellant charge has a maximum of impact strength. A support tube of combustible material lines the cylinder inner surface and its forward end receives a projectile that may seat against a bullet support plug, the plug and projectile being secured to the tube inner surface by a film of combustible adhesive. Similar adhesive secures the tube to the molded cylinder, and a primer disc or stub obturator to the tube.

United States Patent Quinlan et al.

[451 Dec. 12,1972

AMMUNITION Inventors: Joseph B. Quinlan, Philadelphia, Pa.; John J. Scanlon, Jr., Monroe, Conn.

The United States of America as represented by the Secretary of the Army Filed: Nov. 25, 1970 Appl. No.: 92,758

Related US. Application Data Continuation-impart of Ser. No. 749,642, Aug. 2, 1968, abandoned.

Assignee:

US. Cl ..102/40, l02/DIG. 1, 102/44 Int. Cl ..F42b 9/16 Field of Search ..l02/38, 43, 44, 100, 101, DIG.

References Cited UNITED STATES PATENTS l/l97l Quinlan ..l02/38 3,397,637 8/1968 Bobinski 102/38 3,547,001 12/1970 Stoner 102/38 3,345,945 10/1967 Quinlan et al. 102/38 3,396,658 8/1968 Scanlon, Jr. et al. ..l02/DlG. 1 3,565,008 2/1971 Gulley et al. 102/43 Primary Examiner-Samuel W. Engle Attorney-Harry M. Saragovitz, Edward J. Kelly, Herbert Berl and Sheldon Kanars [5 7] ABSTRACT 6 Claims, 3 Drawing Figures PATENTEDIIEB 12 I912 3.705 549 6 gum 1 JOSEPH a. QU\NLAN JOHN J. $CANLON,JR.

II AT TOKNEYS k INVENTOES,

AMMUNITION This application is a continuation-in-part of application Ser. No. 749,642, filed Aug. 2, 1968, now abandoned.

The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.

This invention relates to ammunition and,more particularly, to caseless and semi-caseless ammunition.

One of the objects of the invention is'to provide improved rounds of caseless and semi-caseless ammunition wherein the molded cylinder of propellant charge is provided with a maximum of impact strength.

Another object of the invention is to provide such ammunition which can be produced at very high rates.

These and other objects, features and advantages will become more apparent from the following description and accompanying drawings in which:

- FIG. 1 is a longitudinal sectional view of a preferred round of caseless ammunition embodying the principles of the invention.

FIG. 2 is a similar view of a semi-caseless ammunition round.

FIG. 3 is a longitudinal sectional view of a modified semi-caseless cartridge.

The round of caseless ammunition, shown generally at (FIG. 1) includes a molded cylinder of propellant charge 11, the inner surface of which is secured to a support tube of combustible material 12 by a film of combustible adhesive 13 that extends the longitudinal length of the cylinder inner surface. The support tube 12 is a double based propellant in sheet form and spirally wrapped, the chemical composition being approximately 55 percent nitrocellulose by weight, 42 percent nitroglyeerine and 3 percent additives. A suitahlc solvent binder is utilized between layers of tube sheet propellant. The tube 12 serves as a forward obturator as well as a shock absorber, increasing the impact strength of and supporting the propellant cylinder 11 which may be constructed of less thickness than heretofore and, after undergoing compression during the fabrication process, contain little or no original binder material. Preferably, a bullet support plug 14 is adhesively secured in a similar manner to the inner surface of support tube 12 at a predetermined longitudinal position therealong for the purpose of bottoming a 7.62 mm projectile 15. The combustible bullet support plug 14 is of molded granular single base propellant consisting essentially of nitrocellulose and an appropriate binder. The rearward portion 16 of projectile is similarly secured by combustible adhesive means 17 within support tube 12 adjacent the forward end of propellant cylinder 1 1. A disc of combustible primer 18 is secured in the tube 12 adjacent the rearward end of the propellant cylinder by a similar film of combustible adhesive 19. Upon assembly, the combustible adhesive film is successively applied to the lateral surfaces of plug 14, projectile 15 and primer disc 18 and the coated elements are securely positioned in the support tube 12. An appropriate amount of combustible adhesive is then applied to the outer surface of tube 12 and the molded propellant cylinder 11 is slid forwardly thereon to its desired position.

In the semi-caseless cartridge, shown generally at 20 (FIG. 2), the same reference characters denote similar elements as denoted in FIG. 1. In lieu of primer 18, the rearward portion of tube 12 has an igniter plug 21 and metal stub obturator 22, preferably of steel or aluminum (anodized or unanodized), secured therein by similar combustible adhesive film means 23, 24. The stub obturator 22 has a centrally apertured nozzle constriction 25, formed with a conically shaped approach surface 25A to minimize the rearward thrust effect upon the weapon bolt face and locking lugs. Obturator 22 has a peripheral recess 26 defining an operative extraction groove which is engaged by a pivoted extractor on bolt 40 that has an appropriate ejection mechanism (not shown). The obturator has a forwardly opening annular recess 27 in flange 27A which seats the rearward end of propellant cylinder 11 and aids the obturator in effecting a positive cartridge seal before ignition. To this end the obturator 22 has a larger peripheral diameter than that of the molded cylinder 11 and is about 0.001 inch oversized relative to the interior of barrel 41 or gun chamber which is thereby provided with a pre-ignition seal. Also, cook-off is minimized since the molded cylinder is prevented from contacting the hot chamber wall. The firing pin orifice 42 in the bolt 40 aligns with nozzle 25 and its primer.

Upon ignition of the cartridge, developed pressure gas acting upon the outer surface portion of groove 27 increases the sealing capacity of the obturator.

In the FIG. 3 embodiment the molded cylinder of propellant charge 30 has an internal support tube 12 secured within a substantial length thereof by combustible adhesive means 13. Propellant cylinder 30 has a closed rearward end portion 31 which is peripherally secured to a brass stub obturator 32 that has a crimped locking flange 32A and is centrally apertured and recessed to contain an appropriate metal primer 33. The stub obturator 32 is peripherally coated with a relatively soft metal, preferably a thin copper plate 34 for providing a positive pre-ignition seal while facilitating chambering of the round in the cartridge chamber.

The projectile 35 has its rearward portion 36 appropriately secured by combustible adhesive means 17 in a mating forward tube portion adjacent the forward end 37 of the hollow propellant cylinder 30.

We wish it to be understood that we do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

We claim:

1. In a round of ammunition having a molded cylinder of propellant charge, said cylinder having a forward end and rearward end,

a support tube of combustible material lining an interior surface portion of said cylinder, said support tube having a substantially cylindrical surface at its forwardmost end,

a projectile having a portion secured within said support tube forwardmost end, and

a stub obturator secured in said support tube adjacent said cylinder rearward end, said stub obturator having a nozzle constriction and means for minimizing rearward thrust upon said obturator including a conically shaped surface extending forwardly from said nozzle.

2. The structure of claim 1 wherein combustible adhesive material extends between said support tube and molded cylinder.

5. The structure of claim 1 wherein combustible adhesive material extends between said stub obturator and said support tube, and said support tube is a double based propellant in sheet form.

6. The structure of claim 1 wherein said support tube extends forwardly of said molded cylinder forward end. 

1. In a round of ammunition having a molded cylinder of propellant charge, said cylinder having a forward end and rearward end, a support tube of combustible material lining an interior surface portion of said cylinder, said support tube having a substantially cylindrical surface at its forwardmost end, a projectile having a portion secured within said support tube forwardmost end, and a stub obturator secured in said support tube adjacent said cylinder rearward end, said stub obturator having a nozzle constriction and means for minimizing rearward thrust upon said obturator including a conically shaped surface extending forwardly from said nozzle.
 2. The structure of claim 1 wherein combustible adhesive material extends between said support tube and said cylinder interior surface and between said projectile portion and said support tube.
 3. The structure of claim 1 wherein said stub obturator has a forwardly facing peripheral flange containing a forwardly opening recess, and a portion of said cylinder rearward end is seated against said flange.
 4. The structure of claim 3 wherein the obturator has a peripheral surface diameter larger than that of said molded cylinder.
 5. The structure of claim 1 wherein combustible adhesive material extends between said stub obturator and said support tube, and said support tube is a double based propellant in sheet form.
 6. The structure of claim 1 wherein said support tube extends forwardly of said molded cylinder forward end. 